Compensating hydrometer float



Patented Dec. 13, 1932- UNITED. sfrafriesl HOWARD n. CHRISTIE Ann 'KIBBEY W.coUsn,sor BRONX, NEW YORK;

COMPENSATING 'HYDROME'TER [FLOAT g Application-tiled June 7, 1927. Serial No; 197,192.

This invention relates to a compensating hydrometer float, an objectof theinvention beingV to provide ahydrometer oat which will include means ,causing't to automatically compensate for changes in temperature and thus maintain a constant floating position upon its supporting medium in the presence of temperature changes.

Y A more detailed object is to provide a hy-V medium so that-increase in the loss of supporting quality of the supporting medium, which ordinarily would result in sinking'of the float, will be counteractedv by the proportionate increase in buoyancy ofthe float to thus maintain the float at a substantially constant level.

A further and more specific object is to provide a hydrometer iloatrconstructed to include an air pocket at its lower end adapted to retain a quantity of air in a position where it will be subject to temperature change, and

consequent expansion and contraction, With any change of temperature of the supporting medium or fluid within which the float may be floating. y i

IA further speciiic object is 2to provide means constituting a lflexible confining wally for the mentioned air pocket adapted to always exclude liquid fromvsaidv pocket and yet afford easy expansion of ,they air within said pocket. j y

A further object is Jco-provide simpleand efficient vmeans adapted to `protect thehydrometer float against injury at all times.

A further Objectis to provide protector means including a plurality of lateral .pro-

o forcarryingthe graduations or other indi- 3 jectionsadapted to serve as guide means ffor engaging againstrftheiside walls of the con-- tainer within which the float normally opera es. i Y f f Other objects andV aims of they invention, 55 more or less specific than those referred to above, will be in partJobvious and ,in part pointed out in the course of thefollowing description of the elements, combinations, arrangements i of parts l and applications of 60. principles constituting theL invention.; and the scope of protection.contemplated will be indicatedin the appended claims.

In the accompanying drawing which is tov be taken as a part of this speciiication, and in whichV we have shown kmerely a preferred :form of embodiment of the invention Fig. l is avertical sectional view through a hydrometerioat constructed Ain accordance with thisinvention, and f 70 Fig. 2 is a similar view illustratinga modilied arrangement of parts'.y f n f Referring to the drawing for describing indetailthe structure illustrated therein, and referring irstto the structure Fig, 1,theref erence character L indicates the base or bulbular portionsuch as is found ordinarily in hydrometer floats, thev usual reduced stem portion as l prejecting lcentrally thereabove eating marks as Qthereon, the latter beingk intended to be rea-dl at the level; of the` supporting medium or kliquid in the -usualmanner. f`

Lois arranged the usual weighty materiales 3 which may consist for instance of small lead svt-antially vertical positiony andtheair con- 190 i Within the bottom of the bulbular, portion i tained within the tube G will have no outlet. This air will be there'lore confined within said tube and will be under a slightpressure owing 'to the effort ot the supporting iluid to move upwardly into the tube.

It now the temperature of the supporting liuid, and consequently oi the air contained within the-tube G, is raised said airwillexpand to a degree in proportion to the increase in temperature and will press down the level of the fluid which has entered the lowerend of the tube. This will increase the buoyancy of the float in proportion to the degree to which the level of the lluid within the tubeA f is pressed down and, therefore also in proportion to the increase in temperature and consequent loss ofsupporting quality of the supporting fluid. Y

The loat will thus be readily held automatically at a constant level within the supporting fluid lnotwithstanding changes in temperature of said fluid.

In order to prevent accidental entrance of fluid into the tube G at any time, as well as to insure cleanliness of the interior of said tube, it is proposed that the lower end of the tube may be closed by a closure member as H, said closure member being suitably flexible, as for instance if made of thin rubber or other suitable material, so that it will yield with the changes in bulk of the air contained within the tube G and will in consequence increase or diminish the total exterior bulk of the submerged portion of the float in respense to temperature changes. AThis closure as illustrated preferably extends across the entire under-surface of the tloat and has an annular upturned flange as 7 thereon with a terminal rib as 8 adapted to engage within an annular groove 9 provided to receive it at the margin oi the float.V The portion of the closure which extends across the bottom of the float comprises preferably a disc of thin rubber or like material. It is normally not stretched or under tension, and it is of sui'li cient areaV so that the slight convening and concaving thereof with temperature changes will require little or no stretching of the rul ber. lt is thus rendered extremely sensitive to act in response to the changing pressures within the tube G, which changes are of course only very slight in normal use.

The marginal lanffe portion 7' serves merely to support the main closure or bottom wall part and provide a tight seal against the groove 9 ot the float.

It isimportant to note however that this closure at the lower end of the iloat, being of soit `resilient material, and entirely coveringsaid lower end, provides an excellent protecting `cap or guard member at the lower end ofthe float Jfor preventing possible injury to the tloat during Aany handling thereof.

In the modiiication Fig. 2 an arrangement is shown by which the construction of the glass portion or bulb L is the same as is at the present time ordinary common practice, that is the interior tube G, the annular eX- terior groove 9, etc. as illustrated in Fig. l, are not employed. ln their stead this modification proposes an external jacket substantially entirely enclosing the bulbular portion L of the float, said jacket including annular side walls l() I'or hugging about the annular side walls of the float, and a bottom wall as 11 closing the bottom end of the jacket.

This entire jacket is preferably 'formed of soft resilient and flexible material such as rubber or the like, and it may if desired be provided with one or more sets of laterally projecting lingers `as 1.2-12 thereon for engaging against the interior wall surfaces of a tube such as is usually employed to contain the supporting fluid withinr which the lioat is intended to operate. These lingers may be spaced apart in a row circumterentially oit the jacket and there may be any desired nu1nber of them in each set or row. Theyare of the same resilient flexible material as the jacket and hence provide relatively soft cushion like projections upon the bulbular por tion oi the tloat :tor engaging the walls of the tubular container. They serve to provide only point` Contact between the float and the walls of the container so as to avoid strong capillary attraction as between the tloatjaud said walls as is common with ordinary glass hydrometers.

rlhe bottom end surface as 13 of the bulbular portion L ofthe float substantially semispherical. rlhe side walls l0 of the jacket extend straight downwardly to the substantially flat bottom wall 1l and thus deiine an annular' air pocket ldwithin the jacket between the semispherical bottom wall of the loat and the l'lat bottom wall oi the jacket, the bottoni wall oi the jacket being normally in Contact, or nearly so, with the extreme bottom point of the iioat.

The air which is confined within the air pocket .i constitutes an element oi buoyancy for the float. Its degree ot buoyancy is determined by its bulk, and its bulk is subject to increase and loss under temperature changes so that the bottom wall ll will be converted and concaved, and the bulk and consequent buoyancy ot the completed iieat will be altered by temperature changes et the supporting fluid, the float being thus automatically maintained at a constant level. in the presence ofteinperature changes in the same manner as described with respect to thestructure Fig. 1. j

It is noteworthy that the central tube G illustrated in Fig. l could readily be employed in association with the jacket lO--ll suggested inv Fig. 2, or, inversely. that the jacket l0`ll of Fig. 2 could readily be employed in lieuof the closure H shown in Fig. l.

As many changes could be ,made in this construction Without departing from the scope of the invention, as defined in thefol-` lowing claims, it is intended that all mattert contained in the above description, or shown in the accompanying drawing, shall be in`- terpreted as illustrative only and not in a lim-` iting sense. L

Having thus described our invention, what We claiin as new and desire to secure by Let= ters Patent'isri x 1. A liydroineter float comprising the usua bulbular portion and stem portion, a meme Y bulbular portion and stein portion, and a jacket formed of `flexible material Within Wliicli the bulbular portion engagesand baving parts cobperative with parts of the bulbular portion to define an air pocket associated with the bulbular portion, the parts of said jacket which `co-operate to dciine lsaid air pocket providing a flexible Wall for said air pocket, the degree of flexibility of which permits it Ato flex and thus change the displacement of the float in response to expansion and contraction of the air in said pocket incident to temperature changes of said air in use. y

3. A liydroineter iloat comprising the usual bulbnlar portion and stem portion, and a jacket Within which the bulbular portion engages, said jacket being formed of rubber and Vhaving parts extending free of the bulbnlar portion to provide an air pocket associated with tbe bulbular portion, a part of f said jacket providing a iexible Wall for said air pocket, the degree of flexibility of which permits it to flex `and thus change the displacement of the iioat in response to vexpansion and contraction of the air in said pocket incident to temperature changes of said air in use.

ln testimony vvliereoi:I We aiix our signatures.

HOWARD E. CHRISTIE.l KIBBEYV. COUSE. 

